Chapter 10, Problem 12RQ

Program Plan Intro

ACL:

• ACLs stands for Access Control Lists are a network filter utilized by switches and routers to allow and restrict data flows into and out of network interface.
• After configured ACL on an interface, data passing through an interface is analyzed by the network device and compare it to the conditions described in the ACL, and either allow the data to flow or bans it.
• On most router, every interface must be assigned a separate ACL, and different ACLs may be associated with outbound and inbound traffic. After ACLs are installed on routers, every ACL is assigned a name or number.
• The command “access-list” is used to assign a statement to a pre-installed ACL. This command must identify the ACL and include a deny or permit argument.
• For example, to permit ICMP traffic from any IP address to any other IP address is “access-list acl_2 permit icmp any any”.
  • Here, “access-list” command is used to assign a statement to a pre-installed ACL.
  • The “acl_2” is a name.
  • The “permit” is used to allow the data flow.
  • The “icmp any any” means allow the data flow traffic from any IP address to any IP address.